fix(console): a model the server has not vouched for is not offered as runnable (#136)

* fix(console): a model the server has not vouched for is not offered as runnable

Before the catalog arrived, and for the life of the tab if its one read failed,
the picker treated unknown as available and offered the placeholder list as
runnable; a model picked in that window was refused at the send after it had
been accepted. Availability is now three answers, yes, no and unknown, the
pickers say "checking providers" while it is unknown and offer nothing, and the
catalog read retries three times before giving up.

Ported from the hosted console (fc715f0d); the Arena site of that change has no
counterpart here.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H3iubVywYh1U8ca9Scytff

* chore: start checks

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H3iubVywYh1U8ca9Scytff

---------

Co-authored-by: richard-epsilla <richard@epsilla.com>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Co-authored-by: richard-epsilla <131846445+richard-epsilla@users.noreply.github.com>